1. Technical Field
The present invention relates to conveyers, particularly to wafer box conveyers.
2. Related Art
Usually, wafer fabs use wafer boxes to accommodate wafers and convey those wafer boxes between storage chests and wafer box loaders by conveying carts. However, human-operated conveying carts are uneconomical because they are easy to cause damage to wafers and operators, especially when wafers are larger and larger in size.
A conventional wafer box conveyer includes a frame, a horizontal moving unit, a vertical moving unit, at least one tray and an interlock mechanism. The frame has a horizontal cage with wheels. The horizontal moving unit includes a horizontal rail on the horizontal cage, a horizontal sliding block on the horizontal rail and a first shaft on the horizontal sliding block. The vertical moving unit has a vertical rail disposed on the horizontal sliding, a vertical sliding block on the vertical rail, and a second shaft on the horizontal sliding block.
However, such a conveyer tends to cause damage to the wafers thereon because of vibrations resulting from an uneven floor.